Classification of Bricks | Types of bricks

Classification of Bricks

Understanding First Class, Second Class, Third Class, and Fourth Class Bricks used in civil engineering and building construction.

Introduction

Bricks are one of the oldest and most widely used construction materials in civil engineering. They are used in foundations, walls, pavements, arches, and various structural and non-structural applications.

Depending upon the manufacturing process, strength, shape, surface finish, and water absorption characteristics, bricks are classified into different categories.

Proper classification of bricks helps engineers and builders select suitable bricks for different types of construction works.

1

First Class Bricks

First class bricks are the highest quality bricks used in superior construction works.

Characteristics

• Table moulded and kiln burnt
• Uniform shape and smooth surface finish
• Sharp edges and right-angled corners
• Free from cracks and flaws
• High durability and strength

Crushing Strength: ≥ 10 N/mm²

Water Absorption: 12–15% of dry weight

Uses

• Load-bearing structures
• Architectural masonry works
• High-quality residential buildings
• Reinforced brickwork

2

Second Class Bricks

Second class bricks are moderate quality bricks generally used where plastering is provided.

Characteristics

• Ground moulded bricks
• Slightly irregular shape
• Rough surface finish
• Minor cracks and distortions may exist
• Moderate strength and durability

Crushing Strength: ≥ 7 N/mm²

Water Absorption: > 22.5%

Uses

• Ordinary building construction
• Internal wall construction
• Plastered masonry works
• Temporary structures

3

Third Class Bricks

Third class bricks are low-quality bricks manufactured by poor burning and moulding processes.

Characteristics

• Ground moulded
• Rough and irregular surface
• Soft texture and low strength
• High water absorption
• Not suitable for damp conditions

Crushing Strength: ≥ 5 N/mm²

Water Absorption: > 25%

Uses

• Temporary structures
• Rural construction works
• Non-load-bearing walls
• Structures with short service life

4

Fourth Class Bricks

Fourth class bricks are over-burnt and badly distorted bricks unsuitable for masonry construction.

Characteristics

• Over-burnt during manufacturing
• Irregular shape and size
• Very brittle in nature
• Dark colored due to overheating
• Not suitable for structural work

Main Use: Ballast and road foundation works

Uses

• Road sub-base material
• Aggregate substitute
• Foundation filling works
• Ballast applications

Comparison of Different Classes of Bricks

Property	First Class	Second Class	Third Class	Fourth Class
Moulding	Table moulded	Ground moulded	Ground moulded	Over-burnt
Strength	High	Moderate	Low	Very Low
Water Absorption	12–15%	> 22.5%	> 25%	Very High
Main Use	Permanent structures	Ordinary construction	Temporary works	Ballast and filling

Importance of Brick Classification

• Helps in selecting suitable bricks for construction
• Ensures structural safety and durability
• Improves quality control in masonry works
• Reduces construction defects and maintenance issues
• Supports economical and efficient construction planning

Conclusion

Bricks are classified into four major categories based on their manufacturing quality, strength, and durability. First class bricks provide superior performance for permanent structures, while second and third class bricks are suitable for ordinary and temporary works respectively. Fourth class bricks are mainly used as ballast material due to their poor structural properties.

Proper understanding of brick classification enables engineers, architects, and builders to select appropriate materials for safe and economical construction.

Author

Mohan Dangi
Civil Engineer | Geotechnical Engineering | Content Creator

References

1. B.C. Punmia – Building Construction
2. S.K. Duggal – Building Materials
3. IS 1077: Common Burnt Clay Building Bricks
4. National Building Code (NBC) of India
5. Standard Civil Engineering Materials Manuals

Disclaimer

This article is intended for educational and informational purposes only. The specifications and values mentioned may vary depending on regional standards, manufacturing practices, and applicable codes. Readers are advised to refer to relevant IS codes and professional guidelines before using the information in practical construction works.